Recently, electronic devices or portable terminals tend to be further miniaturized and handheld computerized due to a rapid development of hardware and software such as semi-conductor technologies, information processing technologies, communication technologies, etc. Therefore, a data input in various kinds of electronic devices or portable terminals gradually becomes more important. However, input devices in these electronic devices or portable terminals have some problems of inputting various kinds of data. For example, a keyboard type input device used in a Personal Computer (PC), a Notebook, a Netbook, etc. has a limit to reduce the size, so that there is a difficulty in miniaturization of the size of the electronic devices.
In addition, an input device of a touch screen type used in a Personal Digital Assistant (PDA), a Smart Phone, etc. has a difficulty in performing works requiring fast speed because its input speed is slow when various kinds of data are inputted during office work, web work, games, etc.
Furthermore electronic devices or portable terminals use a certain part of the screen in a display unit as an input interface at the time of input. Therefore, workability on the display unit screen becomes lower, which causes inconvenience.
Moreover, it is not easy that as soon as a finger is put on an input unit or an input surface of cellular phones, portable terminals, etc., whole input selecting positions of each input key or input button are recognized through a fingertip, so that users feel difficulty in easily and quickly performing a continuous input operation at the time of input.
Besides, when one phoneme or data input is performed in an input device through an one-time input operation, Hangeul, that is, the Korean alphabet, requires more than twenty four input keys or buttons for inputting characters to be arranged on the input device, English does more than twenty six input keys or buttons, and Japanese or other languages does input keys or buttons more than Hangeul or English. In addition, as miniaturized electronic devices or portable terminals are advancing to handheld POs, the electronic devices or portable terminals are increasingly demanded to have an input device which can input all the data of a conventional keyboard including characters, a variety of command keys such as Enter key, Space key, Shift key, Conversion key, etc., function keys (F keys), special keys, specific function keys, symbols, etc. Furthermore, the electronic devices or portable terminals, which are remarkably advancing day by day, are facing a more important problem in which a display unit screen and a configuration of an input device are in proper harmony together while at the same time size adjustment and disposition are achieved. Specifically, although it is preferred that small electronic devices or portable terminals, which are relatively smaller than fixed type electronic devices, configure a display unit screen to be larger as users increasingly make a demand for a larger screen when using multimedia or video data, an input device cannot be provided larger than a predetermined size so as to be suitable for portability.
For this reason, conventional cellular phones or portable terminals are so configured that finger-sized keys or buttons are arranged less than the number in a predetermined formation such as 4×3 or 5×3, etc., and a number of data of Hangeul, English, or other languages are respectively assigned to the input keys or buttons in an overlapping manner, so that users can input a data by repeatedly selecting a corresponding input key several times when inputting desired data.
For example, input methods such as Cheon-Ji-In Hangeul, EZ Hangeul, SKY Hangeul, etc. are developed and used. However, the Cheon-Ji-In Hangeul input method has an advantage that reduces the number of input buttons to which data are assigned because desired data are generated by means of a combination of predetermined basic data, and, conversely, a disadvantage that increases input time and typing errors according to a lengthened moving line because a data input is performed not by means of an input operation having a short moving line in a state in which whole input selecting positions are respectively recognized at the time of data input, but by means of an input operation continuously moving a finger to each corresponding input button among a number of the input buttons untouched to a finger.
In addition, although there has been suggested an input method technique such as a keyboard which can be carried with being rolled up or folded, this input device always carried, thereby causing great inconvenience.
Moreover, there has been suggested an input method technique such as a virtual keyboard performing an input by projecting a keyboard Image onto the position of a predetermined space and sensing input operations of fingers on the image in a three-dimensional way.
However, these kinds of input devices can perform a data input in a predetermined space or designated position only, thereby having a difficulty in being applied to mobile electronic devices which can perform an input work at anytime and anywhere.
As described above, electronic devices or portable terminals are required to make input devices to be more miniaturized or compact so as to be used more conveniently while in motion, and the needs of users to portability and convenience is more and more getting increasing. In other words, there is a growing demand of the input device which can use a whole screen of a display unit better and input the desired data more easily and quickly at the time of input.
Considering such a situation, the electronic devices or portable terminals are required to configure an input device providing an input unit in which en input surface having a number of input selecting positions is recognized as one input unit, and the whole input selecting positions are recognized around the middle of a fingertip when a finger is put on the input unit, so that each of the input selecting positions can be individually or continuously selected in an easy and quick manner by means of a short input moving line of a finger and an input operation according to the position recognition at the time of input.